diy solar

diy solar

Struggling with basic LiFePO4 settings in Epever Tracer

Its clear from the waveform that as soon as the battery volts exceeds 13.8 the BMS shuts down charging. You could try lower, say 13.6 volts, the boost duration is not the cause of the problem

Because you are charging with a low current, the battery is almost full when the voltage exceeds 13.8. Due to a BMS fault or incorrectly balanced or faulty cells, the BMS stops the charge.

The app should show the 4 cell volts and on the battery state page the number of protection shutdowns.

It's a battery fault and the supplier needs to sort out the problem with a replacement battery.

Mike
 
If the four series cells in a 12v battery are not balanced the BMS will pull the plug when any cell exceeds its max voltage limit during charging This will happen when nearing full overall charge voltage on battery array.

If these are self contained 12v battery packs (four series cells internal) that you cannot get to individual cells you have to rely on BMS internal balancing. These have relatively low balancing current dump, maybe 50 mA to 100 mA and it only activates when a cell gets higher then 3.4v individually. If you charge at current higher then this BMS balancing bleed current, the bleed current will be overwelmed by higher charge current driving the cell at highest state of charge beyond its high voltage cutoff voltage trip point.

Initially, use lower absorb voltage, around four times 3.4v = 13.6v at lower charge current rate. This allows more time to balance cells. Let it soak for day at 13.6v then raise it to 13.8v and soak it aqain. Eventually the cells should come into balance and you can run normal charging current and voltage without BMS tripping out for high single cell voltage.

If the battery has been abused it may be difficult to keep the cells in balance.

As an aside, a charger that only has timed absorb (boost) phase should be avoided for Li-Ion batteries. Timer only based absorb cycle was commonly used for lead-acid battery chargers. Charger for Li-Ion battery should terminate absorb charge phase based on current sense when charge current tapers off to avoid over charging. If charger only has absorb timer then either set absorb time to shortest possible or do not use absorb cycle and only use float at 13.8v for charging. If you try to use time only based absorb cycle at 3.60v per cell (14.4v for 12v battery) with a strong charge current it will likely damage the battery over tiime and will often get BMS shutdowns for a cell over-voltage limit being reached.
 
It great that everybody is trying to help, but the fact is that the guy bought a 'drop in' lithium battery that is specified to charge at voltages up to 14.6 volts. It cannot charge over 13.8 volts due to a battery fault.
If it were a DIY battery that there are all sorts of workarounds one could try.
Its a fairly resent purchase from a small company in Germany importing ready built batteries.
In Europe we have strong regulations that protect the buyer, in this case the seller must provide a replacement or refund.

Mike
 
It great that everybody is trying to help, but the fact is that the guy bought a 'drop in' lithium battery that is specified to charge at voltages up to 14.6 volts. It cannot charge over 13.8 volts due to a battery fault.
If it were a DIY battery that there are all sorts of workarounds one could try.
Its a fairly resent purchase from a small company in Germany importing ready built batteries.
In Europe we have strong regulations that protect the buyer, in this case the seller must provide a replacement or refund.

Mike

Thanks!
Yesterday I sent a long e-mail to the seller, and I was asking for a new battery or refund..
And was referring to this thread, where we established that the battery is faulty..
I have some screenshots..

First my mail
mail 1.png

And this is the answer, first from the seller, and he sends a reply question to the manufacturer.
It doesn´t seem that he is willing to do something about it.. just yet...

mail 2.png
 
Alternately, when a BMS shuts down for a cell exceeding max voltage limit, the balancer in BMS should continue to bleed the cell that went overvoltage while the other lower state of charge cells do not get any bleeding current. You have to leave some rest time for bleeding to do its job before attempting to charge again or it will just shortly trip for the overvoltage cell again, without giving charge time to bring up lower state of charge cells.

This should work its way into balance eventually. It is not a great way to balance as it may take several charging BMS shutdowns, follow by resting delay period for the bleeding balancer to work on over-voltage tripped cell(s).
 
As an aside, a charger that only has timed absorb (boost) phase should be avoided for Li-Ion batteries. Timer only based absorb cycle was commonly used for lead-acid battery chargers. Charger for Li-Ion battery should terminate absorb charge phase based on current sense when charge current tapers off to avoid over charging. If charger only has absorb timer then either set absorb time to shortest possible or do not use absorb cycle and only use float at 13.8v for charging. If you try to use time only based absorb cycle at 3.60v per cell (14.4v for 12v battery) with a strong charge current it will likely damage the battery over tiime and will often get BMS shutdowns for a cell over-voltage limit being reached.


Which solar charge controllers have the possibility to measure current like you are talking about...?
Can Victron do this?
 
I believe Victron uses timed absorb but done at about 3.5v per cell. Their reasoning is to allow time for BMS to do balancing based on many BMS's using 3.4v for start of balancing. Timed absorb is not so bad when done at moderately lower absorb voltage between 3.4-3.55v. Avoid a 2 hour timed absorb at 3.65v per cell as it can overcharge cells. The amount of time in absorb for charge current taper-off depends on bulk charge current rate. The greater the bulk charge current the longer the absorb current taper-off time once reaching absorb (boost) constant voltage charging.

The approach depends if your BMS has ability to adjust the start of balancing voltage. If you can lower start of balancing down to about 3.35v per cell you don't have to run the timed absorb period so long for balancing time. The lower start of balancing gives a little more time to balance before the highest state of charge cell hits max voltage trigger. Also, the greater the BMS's balancing current dump, the less time for balancing is needed.
 
Last edited:
Hello everyone and congratulations on your competence. Before I start writing, please excuse my bad English.

I would like to ask your opinion on the parameters I set in the Epever Tracer 3210AN user profile to charge a LiFePO4 battery that I built with 4 nominal 3.2 Ah CALT cells, 150 Ah BMS JBD and Active Balancer I don't remember which brand. I have 500 Wh of photovoltaic panels.

I do not foresee large instantaneous absorption (at most 30 Ah) and to load a lot of current (also here at maximum 50 Ah) therefore the cells should never show great imbalances.

The parameters should satisfy my need to have the battery as charged as possible at the end of the day because at night (in summer every night) I have to take 120/130 A from the battery + the normal evening absorption due to lights, compressor refrigerator, etc. etc. .
The use is daily and I don't spend long periods without using it. When this happens, I drain the battery to 50% and unplug it.

Having said that, I will post the calibration of the regulator and that of the BMS and await your judgments and suggestions.
Thank you


Battery type: User
Rated voltage: 12 V
Temperature compensation coefficient: 0 mV/°C
Charge limit:14.4 V [3.6 V x cell]
BOOST TIME: 20 minuts

Over-voltage disconnect: 14.3 V [3.575 V x cell]
Over-voltage reconnect: 14.2 V [3.55V x cell]

BOOST CHARGE:14.1 V
FLOAT CHARGE:13.6 V
BOOST RECONNECT:13.4 V

Equalisation charge:13.8 V
EQUALISE TIME: 0 minuts (disabled)

Low-voltage reconnect: 12.4 V [3.1 V x cell]
Under-voltage reconnect: 12.4 V [3.1 V x cell]
Under-voltage warning: 12.2 V [3.05V x cell]
Low-voltage disconnect: 12.2 V [3.05 V x cell]
Discharge limit: 12.1 V [3.025 V x cell]
 

Attachments

  • Screenshot_20210624-093913_xiaoxiang.jpg
    Screenshot_20210624-093913_xiaoxiang.jpg
    114.4 KB · Views: 30
Last edited:
I emailed support@epsolarpv.com


Thanks for reaching EPEVER. Above you can see the history of what you asked for. You can directly reply to this Email for your question, and we will provide responses as soon as possible.

The only way to limit charge current to 50 Amps is: change the PV module configuration, with the total power of the PV module/system voltage ≤ limit current.

And the fuse between the controller and battery bank should be equal to 1.5 to 2 times of the maximum charging current, 50A is too small.

The MT50 can set most of the control parameter except the "Lower Temperature Charging Limit" and "Lower Temperature Discharging Limit", so please make sure the ambient temperature which your battery installed is never lower than the protection values of the BMS.

I have attached the "Lithium Battery parameter setting rules-V1.0" for your reference, but due to the Lithium battery characteristic, the battery parameter from companies are different, and this file is ONLY for reference, please contact the battery manufacturer to confirm whether your settings are feasible, thanks in advance and have a wonderful day!

Best Regards
Bianca Chen
EPEVER Support996873F9-973F-4B78-A7C7-997CADD43107.png
 
I emailed support@epsolarpv.com


Thanks for reaching EPEVER. Above you can see the history of what you asked for. You can directly reply to this Email for your question, and we will provide responses as soon as possible.

The only way to limit charge current to 50 Amps is: change the PV module configuration, with the total power of the PV module/system voltage ≤ limit current.

And the fuse between the controller and battery bank should be equal to 1.5 to 2 times of the maximum charging current, 50A is too small.

The MT50 can set most of the control parameter except the "Lower Temperature Charging Limit" and "Lower Temperature Discharging Limit", so please make sure the ambient temperature which your battery installed is never lower than the protection values of the BMS.

I have attached the "Lithium Battery parameter setting rules-V1.0" for your reference, but due to the Lithium battery characteristic, the battery parameter from companies are different, and this file is ONLY for reference, please contact the battery manufacturer to confirm whether your settings are feasible, thanks in advance and have a wonderful day!

Best Regards
Bianca Chen
EPEVER SupportView attachment 55516
F3E89A49-06AF-4FBE-9958-42229C9DFB46.png05A26AEB-8086-4CDA-B094-F71EF3A2E743.png
 

Attachments

  • 97BB36A9-F568-44FE-BCC8-4C824855C9C2.png
    97BB36A9-F568-44FE-BCC8-4C824855C9C2.png
    175.5 KB · Views: 64
I emailed support@epsolarpv.com


Thanks for reaching EPEVER. Above you can see the history of what you asked for. You can directly reply to this Email for your question, and we will provide responses as soon as possible.

The only way to limit charge current to 50 Amps is: change the PV module configuration, with the total power of the PV module/system voltage ≤ limit current.

And the fuse between the controller and battery bank should be equal to 1.5 to 2 times of the maximum charging current, 50A is too small.

The MT50 can set most of the control parameter except the "Lower Temperature Charging Limit" and "Lower Temperature Discharging Limit", so please make sure the ambient temperature which your battery installed is never lower than the protection values of the BMS.

I have attached the "Lithium Battery parameter setting rules-V1.0" for your reference, but due to the Lithium battery characteristic, the battery parameter from companies are different, and this file is ONLY for reference, please contact the battery manufacturer to confirm whether your settings are feasible, thanks in advance and have a wonderful day!

Best Regards
Bianca Chen
EPEVER SupportView attachment 55516
I asked about limiting the Equalisation time to zero:
Please set the Equalize Charging Voltage to be as same as the Boost Charging Voltage, includes the Equalize Charging Time.

Best Regards
Bianca Chen
EPEVER Support
 
Hello all. I am struggling to justify some basic LiFePO4 charging parameters, and relate them to how to set up my Epever Tracer 2215BN. The Epever has many charge parameters geared toward charging older chemistries. This is very confusing to apply to LiFePO4, and the fact that terminologies and recommendations for charging LiFePO4s are all over the place makes it even more difficult.

Can someone please help with some very fundamental questions?

The tracer needs settings for:

1) Charging limit voltage (is this the same as "bulk"?)

2) Equalize voltage (ok, I get that this is to be turned off with a zero duration setting)

3) Boost voltage (what is this? something else to be zeroed out like equalize?)

4) Float voltage (seems straightforward, no questions here)

Will seems to recommend an Absorption cycle and a Float cycle. Which Epever cycle is "absorption"?

Relion recommends a Constant Current cycle and an absorption cycle. Which Epever cycle is "constant current," and which is "absorption"?

Battle Born's docs seem to have use for the Boost cycle, at 14.6V with a 180 minute duration. How does this square with what Will and Relion recommend?

I have a feeling that the answers are simple, but I'm finding it very confounding. I bought the Epever at Will's recommendation, but am finding it not at all beginner-friendly for LiFePO4s. I'm on a low budget, charging two Miady 16AH batteries in parallel, they seem very promising for my application so far, and I just want to give them the best chance for long-term success.

Anyone?

Thanks, Doug
Hey! Got this information from epever. Anyone have any objections to this?
Hello all. I am struggling to justify some basic LiFePO4 charging parameters, and relate them to how to set up my Epever Tracer 2215BN. The Epever has many charge parameters geared toward charging older chemistries. This is very confusing to apply to LiFePO4, and the fact that terminologies and recommendations for charging LiFePO4s are all over the place makes it even more difficult.

Can someone please help with some very fundamental questions?

The tracer needs settings for:

1) Charging limit voltage (is this the same as "bulk"?)

2) Equalize voltage (ok, I get that this is to be turned off with a zero duration setting)

3) Boost voltage (what is this? something else to be zeroed out like equalize?)

4) Float voltage (seems straightforward, no questions here)

Will seems to recommend an Absorption cycle and a Float cycle. Which Epever cycle is "absorption"?

Relion recommends a Constant Current cycle and an absorption cycle. Which Epever cycle is "constant current," and which is "absorption"?

Battle Born's docs seem to have use for the Boost cycle, at 14.6V with a 180 minute duration. How does this square with what Will and Relion recommend?

I have a feeling that the answers are simple, but I'm finding it very confounding. I bought the Epever at Will's recommendation, but am finding it not at all beginner-friendly for LiFePO4s. I'm on a low budget, charging two Miady 16AH batteries in parallel, they seem very promising for my application so far, and I just want to give them the best chance for long-term success.

Anyone?

Thanks, Doug
Hey! Got this information from epever. Anyone have any objections to this?
 

Attachments

  • 48v lifepo4 16s settings.JPG
    48v lifepo4 16s settings.JPG
    202.1 KB · Views: 142
For what its worth, when I decided to replace my AGM's with LiFePo4 I was told by EP Solar the BN was not suitable for lithiums. I was advised to replace it with their XTRA series MPPT which I did. One other thing of note, the settings they give for lithiums do not play well with Overkill BMS'.
 
. Anyone have any objections to this?
Me.
The charge voltage is too high and the BMS/cells may/will not play nice.
I suggest,
boost 56 volts (55.5 to 56.8 volts),
float 53.6 , (53.4 to 54.0 volts)
boost reconnect 0.4 volts lower than float
boost duration, 0 to 30 mins (High charge currents need the longer time)
equalise set to same as boost

All the other settings relate to the load outputs of the controller and set as required. Only the above 5 settings determine how the battery is charged.

These conservative settings are my preference, others may have requirements that use more aggressive charge voltages.

Mike
 
For what its worth, when I decided to replace my AGM's with LiFePo4 I was told by EP Solar the BN was not suitable for lithiums. I was advised to replace it with their XTRA series MPPT which I did. One other thing of note, the settings they give for lithiums do not play well with Overkill BMS'.

I'm finding this out...started searching...found this thread.
@mikefitz clarified that boost duration starts AFTER the battery has reached boost set voltage. Dear lord, I had it set for 10 minutes - and boost ran for 35 minutes. I thought WTH. This is when I really started digging. The program will not let you set the minimum to less than 10 minutes - found out the hard way by testing the software.

And yeah, their settings don't go with Overkill very well - I have a 4S 120A. High charge voltage makes the full cells over-volt and it shuts down charging.


My Eve LF230 cells got top-balanced to 3.65V, zero amps, pack got built, new converter/charger installed, new solar setup with the new style Tracer Xtra 3210N.
I've been shaking my head and asking a lot of questions, and there's a LOT of confusion on these charge settings.

Here's a few things I found out the hard way...
1. You cannot do ANY custom programming on this unit without the XT50 display or the USB cable and a PC. I understand there's a wifi or BT dongle as well for android, but I skipped all that. Bottom line is you cannot just push buttons to program these new models. The older AN you can - I also have a 1206AN, the 10A mppt - it's the older Tracer model and you can set user parameters with the unit buttons. But it is WAY easier to use the EPEVER controller monitor software.

2. Boost duration - covered. It starts when the battery reaches boost voltage setting on the controller. I suggest you analyze how long you want your lifepo pack to continue to be charged at peak voltage.

3. In my case the Overkill bms starts balancing too high, so with a short boost duration there's no time for balancing. Once the battery gets to 98% of full charge the controller drops to float. Worse, any cell voltage above about 3.5V one or more of them are at fully charged volts and their voltage starts shooting up. Left to continue, the BMS will shut charging down to the whole pack for over-voltage.

4. I am going to try lowering BMS balance on charging to 3.4 if it isn't already, and see if I can get my cells to better balance at high SOC. And lower the boost charge voltage to 14.0 to try to prevent voltage run-away from fully charged cells. Hopefully this will give the BMS some more time to actually do some balancing before any of the cells peak out.

Otherwise I find the controller behaves as expected. You can float at whatever level you want - 3.3 to 3.4 per cell, depending on whether you're resting the pack or servicing a load. And your boost reconnect should be set so that your load is serviced some before the full charging boost and absorption modes start over.

Can someone also confirm that this boost mode starts over each day when the SCC is activated from the PV with some current? I have not been able to test this yet.

It took a lot of searching to find good solutions and answers on this SCC. This thread is invaluable. (y)
 
I can confirm that once the Tracer enters float mode, as long as it stays powered up, it stays in float unless or until the battery reaches the reconnect voltage. I left my PV's shut off 'till today at lunch, flipped the breakers, and Tracer Xtra was still in float mode - happily putting enough current to maintain my 13.4V float setting. The charge cycle does not start each day.

I do seem to recall some text in the manual about it going into boost mode for 15 minutes after so many days to make sure the battery stays fully charged. I have not tested or confirmed this. But is no problem, it will boost then float again.

In float, it does feed in current for any intermittent loads. If the load takes the pack below your reconnect setting it will do the full boost mode charging sequence.

I also confirmed that top-balancing is critical for higher charge voltages, otherwise your highest cell will trip the BMS. I top-balanced my pack last night with a resistance load on the high cells (an auto headlamp bulb and leads) to bring them inline with the others. I put my boost level charging back to 14.1, float at 13.4, and reconnect boost at 13.2. Boost duration at 10 minutes - the lowest duration the program allows. For daily use where you have appliances and loads, I would use a 13.6 float just to keep the pack a little higher. 13.4 sits about 97% according to my Overkill BMS. 13.2 would be a good storage setting.

Based on all of the data here, and my testing, I think I will have two parameter files I can select from and load into the SCC - one for traveling and using the coach with higher charging, and one with lower settings for storage/maintenance. It takes just a moment to import a profile and update the controller. I'll leave my second controller for my portable deployable panels to the 'away mode' since they only get used when we're dry camping. And I think I'll set my Victron Orion to similar away parameters for when we're driving.
 
My Eve LF230 cells got top-balanced to 3.65V, zero amps, pack got built, new converter/charger installed, new solar setup with the new style Tracer Xtra 3210N.
Not to put anyone on the spot here but I just sent back my two standard Tracer X201N controllers and ordered the XTRA models instead. I am hoping when you say "new style Xtra" is a better solution that there is not an old style xtra and a new style xtra, otherwise I am going to get penalized I believe if I return one more solar controller. I've got the EVE 4s 280aH and the JBD 200a BMS. Please tell me I made the right decision. (Sent you a PM, thanks).
 
Can anyone address using an Epever controller and which one will work the best for 4s 280hH LifePo4 on a JBD 4s 200 BMS? This thing is taking on a life of its own (this project) and if I don't put it to rest soon, I think I am going nuts :)
 
Looking for verification that the xtra line is the suggested solution to the 4s 280aH individual cells along with the JBD 200 BMS. Thanks in advance.
 
Epever is just one option. Lots of people like Victron components, and others.
Overall I’m happy with mine, an older style AN and the Xtra mppt controllers.
Frankly I think they’re more similar than different, they all use the same programming software for charge parameters, which gives fits for some. Get the cable or dongle and a laptop to adjust charging to suit your situation. All of these packs/builds are a little different.
Start a build thread for help and questions if you need or want to. There can be complications to work through, and patience will serve you.
 
Back
Top